Submarine rescue and escape mechanism



Jan. 4, 1944. c; n. PLEAK SUBMARINE RESCUE AND ESCAPE MECHANISM y 5Sheets-Sheet 1 File'd Feb. 12, 1940 ATTORNEY J Jan. l4, .1944. c. D.PLEAK VSUBIMRINE REscE AND' ESCAPE MEGHANISM 5 snets-sheet 2 Filed Fe.12, 1940' ou. R Y mkv. E m e. M, V/e. m mf A M f ww Y B 7 u...

Jan.. 4, 1944. Q D, PLEAK 2,338,597

SUBMARINE RESCUE AND ESCAPE MECHANISM Filed Feb. l2, 1940 5 Sheets-Sheet3 ATTORNEY.

Jan. 4,/ 1944,. c. D. PLEAK z338,597

SUBMARINE RESCUE AND ESCAPEMECHANISM Filed Febjlz, 1940 5 sheets-'sheets NVENTOR. Carra/ fea,

ATToRNEYs.

Patented Jan. 4, 1944 UNITED STATES PATENT OFFICE S'UBMARINERESCUE ANDESCAPE MECHAN ISM 3 Claims.

The present invention relates to submarine rescue and escape mechanism,and the primary object of the invention is to provide mechanism, carriedupon a submarine vessel, and operable entirely from within the vessel,whereby the crew may escape to the surface from a disabled submarine,and whereby a buoy may be projected to the surface, carrying with itsignalling mechanism and means whereby air may be pumped from thesurface to the submarine, whereby telephone communication can beestablished with the surface, and whereby electrical power may beconducted from the surface to the submarine for use aboard the disabledvessel. Further objects of the invention will appear as the descriptionproceeds.

To the accomplishment of the above and related objects, my invention maybe embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstruction illustrated and described, so long as the scope of theappended claims is not violated.

Fig. 1 is a transverse section, more or less diagrammatic, through asubmarine, showing the arrangement of my rescue buoy and my escape carand the operating mechanism therefor;

Fig 2 is a horizontal section taken substantially on the line 2 2 ofFig. 1 and locking in the direction of the arrow, the buoy and carhaving been removed `for clarity of illustration;

Fig. 3 is an enlarged transverse section showing the manner ofconnection of the rescue conduit with its reel;

Fig. 4 is a top plan view of my rescue buoy in inated condition;

Fig. 5 is a side elevation thereof;

Fig. 6 is an enlarged vertical section through the gas reservoir forminga part of my buoy;

Fig. 7 is an enlarged sectional View of a valve used in connection withthe gas reservoir;

Fig. 8 is an enlarged sectional view of connector means for the conduit;

Fig. 9 is an end view of the connector head at the end of the conduit;

Fig. 10 is an enlarged elevation of the buoyejecting means of myinvention;

Fig. 1l is an enlarged fragmental sectional view of the water-tight sealformed between the escape car and the upper portion of its compartment;

Fig. 12 is a more or Vless diagrammatic view of the reel for the rescuelconduit and its driving'means; and

Fig. 13 is a similar View of the reel for the escape car cable and itsdriving means.

The numerous tragedies which have resulted from disablement of submarinevessels while submerged, have been due primarily to the fact that noeiicient means has been provided heretofore for permitting the escape ofthe crew of the disabled vessel. The rescue bell which has recently comeinto use is marvelously effective once it is properly attached to thedisabled vessel, but, unless all of the circumstances surrounding thevessel are perfect, the bell cannot be attached to the submarine withoutthe services of divers; and often submarine vessels are disabled at adepth such as to make diving impossible. The escape lung is alsoeffective in many cases; but it cannot be used beyond relatively shallowdepths, its use subjects the crew members to submersion in water whichmay be impossibly cold, and it also subjects the users to water pressurewhich may be highly injurious, and which certainly will be injuriousunles the users rise through the water relatively slowly.

When a submarine is disabled while submerged, it sometimes happens thatthe circumstances are such that if suicient electric power could besupplied to the vessel from an outside source, the vessel could beraised. At other times, the circumstances are such that, if sufcient aircould be supplied to the disabled vessel, it would be possible for thecrew to make necessary repairs and bring the vessel to the surface. v

1n attempting to overcome all cf these defects of prior art mechanismsand to provide means whereby air and electric power can be supplied. tothe disabled vessel from an assisting vessel on the surface, I haveconceived the mechanism of the present application.

In the drawings, the hull of a submarine vessel is indicated generallyby the reference numeral 29. A11 such vessels are provided with aplurality of transverse bulkheads at spaced locations throughout thelength of the vessel; and such a bulkhead is indicated at 2i. In theinterest of both space economy and safety, I propose to build my escapeand rescue mechanism into one or more of these bulkheads; and in Fig.2,1 have shown how this can be done. The longitudinal depth of thebulkhead is increased as at 22 by providing walls 23 and 2t to form aroom l5 communicating with the body of the vessel through doors 26 and21. All of the controls for the mechanism of the present invention areyaccessible from within the room 25; so that, even if a part of thevessel is ooded, the doors 26 and 21, or that one of those doors whichis adjacent the ilooded portion of the vessel, may be closed to preventflooding of the room 25, and so that the rescue and escape mechanism ofthe present invention may be operated from the protected room.

A door 28, which is water-tight when closed, provides access from theroom 25 to a water-tight chamber 29 having a long, vertical, cylindricalportion 36 which opens at 3| through an outer wall of the vessel. Theport 3| is normally closed by a hatch 32 of standard and well knownconstruction which may be locked, unlocked, and removed by any knownmechanism for so manipulating hatches. Within the chamber 29 is mounteda reel 33 upon which is wound a flexible, but armored, conduit 34. Thereel 33 is preferably connected to be driven by an electric motor 35,through a gear reduction 36; and one end of the conduit 34 is suitablyconnected to my rescue buoy indicated generally by the reference numeral31 in Fig. 1, said buoy being normally carried in the cylindricalportion 36 of the chamber 29.

The reel 33 comprises a hollow shaft 38 which carries an elbow 39, shownin Fig. 12 and in detail in Fig. 3. The conduit 34 is formed at itsopposite ends with connector heads 46 and 44. The head 40 cooperateswith a connector head 4| on a long tubular element 42 forming a part ofthe buoy, and may be secured thereto by any suitable coupling means suchas the swiveled coupler 43. The head 44 is similarly connected to theelbow 39 through any suitable means such as the swiveled coupler 45. Theconduit 34 is formed to provide an air passage 45, an electric powerline 41, a telephone line 48, and any other desired conductors,extending from end to end thereof. The elbow 39 and the head 44 areformed with cooperating connector elements similar to the elements |52,|53, |54, and |55 of Fig. 8, whereby, when thehead 44 is brought intocooperative relationship with the elbow 39, operative connections willbe established between the gas passage 46 of the conduit and thegascarrying tube 46 in the elbow, between the power line 41 of theconduit and the power line 49 of the elbow, and between the telephoneline 43 of the conduit and the telephone line 59 of the elbow. As isclearly shown in Fig. 12, the conductors 45', 49, and 5|) extend axiallythrough the shaft 38, and are operatively connected through a standardswivel coupler to stationary conductor lines (not shown) The power andtelephone lines will be continued to a central switch board, thecontrols of which will be accessible in the room 25, and the air conduitwill be continued, through valved pipes, to distribute air to desiredportions of the vessel.

Corresponding conductors |48, |49, and |50 extend throughout the lengthof the tube 42, terminating in a coupler head 5|, similar to the head4|, at the uppermost end of the tube 42.

The tube 42 forms a supporting base for the buoy 31 and for the gasreservoir indicated generally by the reference numeral 52 andillustrated in detail in Fig. 6. Said reservoir comprises a cylindricalshell 53 within which are fixed upper head 54 and lower head 55, saidheads being secured likewise to a central sleeve 56 which is sleeved inplace on the tube 42. A base 51, having a plurality of ports 58therethrough, supports the reservoir in position on the tube 42; andsaid base is formed with a radially extending annular flange 59 for apurpose later to be described. At the upper end of the shell 53, thereis provided an annular shoulder '60, the purpose of which also will bedescribed hereinafter.

It will be seen that the base 51 cooperates with the head 55 to providea chamber 6| open to the circumambient medium; and the reason for thiswill appear hereinafter. A nut 62 secures the reservoir assembly inplace on the tube 42.

A bracket 63 is sleeved in place on the tube 42 immediately above thereservoir 52, said bracket and reservoir being provided with cooperatingelements 64 to prevent relative rotation thereof. The bracket 63 isprovided with an upstanding flange 63 to which is secured the lower endof an air-tight bag 66 which should be formed of any available air-tightmaterial capable of being readily folded and collapsed. I prefer to formthe bag 66 of material which is nonelastic; but the essentialcharacteristics of the material are that it shall be air-tight,unaffected by sea water, readily foldable, tough, and of high tensilestrength. The lower end of the bag is secured to the ilange 63' by meansof a band 61 held in place on said ange by a plurality of bolts 68, orthe like; and of course the joint must be air tight.

It will be noted that the upper end of the shell 52 terminates short ofthe bracket 63, leaving a space 69 therebetween, and dening a chamber 10open to the circumambient medium.

Referring, now, to Figs. 4 and 5, it will be seen that the bag 65, whenin inflated condition, is surrounded by a protecting shield consistingof a plurality of toggle elements. When deated and collapsed, the bag 66is much more closely sur,- rounded by the said toggle elements, as isapparent from an inspection of Fig. 1.

Adjacent the upper end of the tube 42 there is secured in place abracket 1|, the same being held in place by a nut 12 or the like. Aplurality of bars or shield elements 13 are pivotally secured to a likenumber of radially projecting arms 14 upon the bracket 1|, said shieldelements 13 being mounted upon pivots 15, the axes of which lie inplanes substantially perpendicular to the axis of the tube 42, and arearranged in an annular series.

Slidably mounted upon the shell 52 is a second bracket 16 formed toprovide a plurality of radially extending arms 11 carrying pivots 18,said pivots being arranged upon axes lying in planes substantiallyparallel with the planes of the pivots 15. A coiled spring 19 surroundsthe shell 52, is supported on the flange 59, and constantly urges thebracket 16 upwardly toward engagement with the flange 6B. A plurality ofshield elements 89, similar to the elements 13, are pivotally mounted onthe pivots 18; and the free ends of the elements are hingedly connectedto the free ends of the corresponding elements 13 by hinge means 8|, orthe like.

Obviously, if the bracket 16 is pressed downwardly against the tendencyof the spring 19, the shell elements 13 and 89 will be straightened andbrought into the positions of Fig. 1, while the bag 66 will becollapsed. However, when the bracket 16 and the shield elements arereleased, the spring 19 will force the bracket 16 upwardly to theposition of Fig. 5, thereby expanding the shield elements.

Suitable latch means (not shown) may be provided for holding the bracket16 in its lowermost position; and if such means is used, the latch mustbe released before the buoy is ejected from the vessel, such releasebeing effected either manually or by automatic means such asa pawlladjacent the mouth'l of the chamber 30.

However, such latch means is not essential; since the shield elementswill be held .in their straightened position, whenever the buoy .is inthe chamber 30, by engagement with the Walls of that chamber; in whichcase, the force of the spring 19 will tend to assist in the ejection ofthe buoy after the hinges 8l have passed the mouth 3| of the chamber 3e.

Returning to Fig. 6, it will be seen that there is positioned in. thechamber 6'! a pressure-responsive instrument 32 which may 4be either adiaphragm or a bellows or a piston. Such element 82, however, supports a`column of liquid in a pipe 84 extending upwardly through the head 55,into the reservoir, and communicating with the lower portion 85 of apressure-responsive valve indicated generally by the reference numeral86. A hand-operated valve 8,3, normally in closed position, preventsmovements of the pressure-responsive element 82 from being communicatedto the valve t6 under normal conditions.

Valve 86 is provided with a port 8l constantly in open communicationwith the interior of the reservoir 52 in which is contained air or othergas under very high pressure. A pipe 88 leads from the outlet port ofthe valve 35 through the head til, through the chamber le, and throughthe bracket 53, to the interior of the bag BS. Another pipe te leadsfrom the interior of the bag 65 to the upper end 9e of the valve 8e.Within the valve housing is reciprocably mounted a piston-type valve elformed with heads 92 and Q3 respectively received in the lower and upperparts of the valve housing, and formed with a passage @il which, in oneposition of the valve, will establish communication between the port 8land the pipe 88.

It will be seen that the head e2 is larger than kthe head 93, and thatthe pressure of the circumambient medium is impressed upon the head 92Whenever the valve 83 is open, while the pressure within the bag 65 isimpressed at all times upon the head 93.

@ne form of valve which may be used at 83 is illustrated in Fig. 7. Asillustrated, such valve may comprise a casing 95 having a passage 9Stherethrough, and formed with an intersecting frusto-conical socket 97in which is received a correspondingly-shaped valve head Q3 formed witha passage 9S therethrough. A stem lili) is connected to the valve head93 and may be provided with an operating handle lei read-ily accessibleto the operator, as shown in Fig. 6.

An escape valve H52 provides a controlled passage from the interior ofthe bag 58 to the chamber "it through the port lee and the port lll. Avalve member H355 controls such flow, being reciprccably mounted in thecase 4t2 and being formed with a passage it registrable in one position,with the port itil. A port HB1 places the lower end oi the valve memberM5 in open communication with the circumambient medium in the chamberle, and the upper end of said valve member is always in opencommunication with the gas in the bag 6in, A spring I e8 tends to holdthe valve member tile in the position illustrated in Fig. 6.

Means must be provided for floodingthe chainber Ee and its extension 3e,since the pressures on opposite sides of the hatch 32 must besubstantially equalized before the hatch can be opened. In Figs. 1 and 2I have illustrated a pipe l Ue leadingrfrom the `exterior of the vesselto the .chamber .29, .a valve I le, accessible from within the room l25,provided to control iiow through vsaid pipe.

Although, once the chamber 29, 3i) is flooded and the hatch 32 isremoved, the buoy 31 will tend to float out of the chamber 30, I preferto provide mechanical means for positively ejecting the buoy. Such meanscomprises a yoke III, illustrated in Figs. 1 and 10, immediately sub-.'iaeent the iiange 59, and a push rod H2 operatively associatedtherewith. As is clearly shown, said push rod is provided with rackteeth I I3 and is mounted to slide through a gear box H4 in which ispositioned a pinion H5 carried on a shaft Ht rotatable by a hand wheelli'l accessible from within the room 25.

In case of an emergency, the door 23 is opened and the handle ll isrotated through 90 to place the pressure-responsive element 32 incontrol of the liquid column in the pipe 813. Immediately, the pressureof air upon the pressureresponsive element 82 will be communicated tothe head 92. Since the effective area of the head Si?. is greater thanthe eiective area of the head 53, and since the pressures existing inthe chamber e! and within the bag 66 are equal, the valve e! will beraised to bring the passage 94 into registry with the conduit 88. Itwill be noted that the passage 94 is small, so that air iiow, eventhough the pressure within the reservoir 52 is very high, will begradual. Immediately after opening valve 83, the door 23 is closed andsealed and the valve liti is opened to flood the chamber 29, 3i). Assoon as the pressure within the chamber 29, 36 substantially equals thepressure upon the outer surface of the hatch 32, the hatch 32 is removedby standard operating means and the hand wheel lll is operated to ejectthe buoy 3?. As the buoy 3l leaves the chamber Se, the spring 'iiiforces the bracket 'i8 upwardly, thereby expanding the shield which,until that time, has acted to prevent the bag t6 from scraping againstthe surfaces of the chamber 3i).

Meantime, air is owing into the bag (it. The pressure now impressed uponthe element 82 is the pressure of the surrounding water; so that airwill continue to flow into the bag et from the reservoir 52 until thepressure within the bag somewhat exceeds the outside water pressure,whereupon the effective pressure upon the head 93 will exceed `theeffective pressure upon the head 92 to return the valve 9i to theposition of Fig. 6. While the differential between pressure within thebag and the water pressure may be any reasonable predetermined amount, Iprefer to proportion the parts so that the valve SI will be returned tothe position illustrated in Fig. 6 when the pressure within the bag 66exceeds the water pressure by approximately eight pounds per squareinch.

The bag 6e is so proportioned that it will readily lift the weight ofthe amount of conduit trl carried aboard the vessel. If desired, and inorder to assist the rise of the buoy, the motor 35 may be operatedduring the rise of the buoy to rotate the reel 33 te feed the conduit tothe buoy.

Gbvio'usly, if the vessel rests upen the bottom at va level such thatthe water pressure is two hundred pounds per square inch, and if apressure of two hundred and eight pounds per square inch is charged intothe bag, the pressure upon the bag is only eight pounds per square inch.if the buoy were permitted to rise to the surface, however, withoutvalving air out of the `bag, the rupturing pressure of the gas withinthe bag would become one hundred and ninety-three pounds per squareinch; and it is impractical to provide a bag made of material capable ofwithstanding such a rupturing pressure. It is for this reason that Ihave provided the valve mechanism |2|9.

As has been stated, the spring |38 tends to hold the valve member |35 inthe position of Fig. 6, as does also the pressure of the circumambientmedium. The pressure within the bag, however, tends to move the valvemember |35 in a direction to bring the passage |43 into registry withthe port |34. l prefer so to proportion the spring |38 that the valvewill be moved to exhaust position when the pressure within the bagexceeds the pressure of the circumambient medium by a value slightlygreater than the pressure differential which will close the valve 9|;for instance, ten pounds. Thus, if we again assume that the buoy isreleased at a point at which the water pressure is two hundred poundsper square inch, it will be seen that the valve |35 remains in closedposition until after the valve 3| is closed. As the buoy rises, thewater pressure will decrease. If gas has been charged into the bag to apressure of two hundred and eight pounds per square inch, the valve |33will remain closed until the buoy has reached a position at which thecircumambient pressure is ninety-eight pounds, whereupon the valve |35will open to discharge some air from the bag. If it be assumed thateverything is perfectly 'air-tight, it will be clear that the valve 9iwill not again be opened as the buoy rises, but that the valve |35 willbe periodically opened, or that it may remain open throughout the riseof the buoy, to prevent the pressure differential between the inside andthe outside of the bag 66 from rising beyond ten pounds per square inch;so that, when the buoy reaches the surface, the pressure within the bagwill be twenty-rive pounds per square inch.

However, if leakage should occur, so that the pressure differentialbetween the inside and the outside of the bag should drop to a valueless than eight pounds per square inch, the valve 3| will again beopened to replenish the supply of air within the bag and to raise thepressure differential again to the eight pound value for which the valve3| is set.

Obviously, the buoy 3l may carry any kind of signalling devices, such aslights, bells, whistles, or radio broadcasting aerials; but theparticular details of such signalling mechanisms form no part of thepresent invention. Once the buoy is located, however, by a rescue ship,which may be provided with 'a conduit similar to the conduit 34, thatconduit may be connected, by the rescue ship, to the head 5|; therebyestablishing a Contact with the disabled vessel through which air may bepumped to the vessel, through which telephone communication isestablished, and through which electric power may be conducted to thedisabled vessel.

In a second water-tight compartment I I8 there is located a reel I uponwhich is wound a cable |23. Within a cylindrical, vertical extension |2|of the chamber I3, there is positioned an escape car |24. The extension|2| opens at |22 through an upper Wall of the vessel, and the opening|22 is closed by a hatch |23 of standard construction.

The car |24 is provided with an exit opening |25 in its upper end,closed by a hatch |26 of standard construction and operable from eitherinside the car or outside the car; and with an entrance opening I2'| inits lower portion, provided with a hatch |28 of standard constructionoperable either from the inside or the outside of the car. The car maybe provided with seats |29, if desired.

Projecting downwardly below the port |2'l is a spider |35 terminating ina collar |3I, or the like, to which is securely fastened an end of thecable |28.

The car |24 and the compartment extension |2| are formed withcooperating surfaces providing a water-tight joint |32, the details ofwhich are illustrated in Fig. 11. As there shown, the compartment wallis formed to provide an upwardly facing annular shoulder |33 bounded atits inner edge by a flange |34. A compressible washer |35 may bepositioned in the channel |33; and the upper portion of the car |24 isformed to provide a downwardly facing channel |36 receiving the upperedge of the flange |34 and a downwardly facing lip |31 adapted to engageand compress the washer |35. It will be obvious that, when the car |24is pulled tightly down against the seal |32, these cooperating surfaceswill prevent the iiow of water into the lower portions of thecompartment IIS, |2|.

A door |38 provides access from the room 25 into the compartment ||8,and a platform |33 is located immediately below that door, providing asupport for a person seeking entrance to the car |24. A conduit |40leads from the outside of the vessel and communicates with a pipe |4I,controlled by a valve |42, and leading into the chamber |43 between theseal |32 and the hatch |23. The conduit |40 also communicates with apipe |44 controlled by a valve |45 and leading into the compartment H8.The door |38, valve |42, and valve |45 are all accessible from withinthe room 25.

When it is desired to use the escape car, the space |43 is ooded byopening the valve |42, and the hatch |23' is thereupon removed. The door|38 and the hatch |28 are now opened and one or more men crawl into theescape car and lock the hatch |28. The valve |45 is now opened to floodthe compartment ||8, |2|; and as soon as that compartment is flooded,the escape car |24 will float out of the compartment and to the surface.Assuming the presence of a rescue ship, the hatch |26 is removed, thepassengers leave the car, and the hatch |26 is again secured. The crewaboard the disabled vessel is now notied by telephone that the car isready for its return trip, and the motor |46, connected to the reel I I9through a reduction gear |41, is operated to drive the reel |I9 to haulin the cable |20. As the car reaches the vessel, it is necessarilycentered by the cable upon the opening |22, and

vis pulled into sealing engagement with the seal |32. Thereupon the door|38 is opened, whereby the compartment 2| will be emptied down to thelevel of the bottom of the door. True, a certain amount of water willthereby be discharged into the room 25; but it will be a relativelysmall amount, since all of the water below the door |38 will be retainedin the compartment IIS.

Of course, this partial draining of the compartment |2| will create anenormous pressure diiferential which will hold the car |24 in sealingengagement with the washer |35.

This operation is repeated until all crew members have escaped from thedisabled vessel.

I claim as my invention:

1. A distress signalling mechanism for submarines comprising' acollapsible buoy adapted to be carried on a vessel in collapsedcondition, a reservoir containing a compressed gas, said reservoir beingcarried on said buoy, conduit means providing communication between saidreservoir and the interior of said buoy, valve means controlling flowthrough said conduit means and comprising an element having a surfacesubject to the pressure currently existing in the interior of said buoyand having a larger opposing surface subject to the current pressure ofthe circumambient medium, said element being movable, under the jointeiect of a pressure within the buoy exceeding the pressure of suchmedium by less than a predetermined value, to open said valve means topermit ow through said conduit, and movable to close said valve meansWhenever the pressure within said buoy exceeds the pressure of saidmedium by more than such predetermined value, and a second valve meanscontrolling communication between the interior of said buoy and thecircumambient medium, and comprising an element having a surface subjectto the pressure currently existing in the interior of said buoy and anopposing surface subject to the current pressure of such circumambientmedium, and movable under the joint effect of a pressure within the buoyexceeding the pressure of such medium by more than a predeterminedvalue, to open said second valve means, but movable to close said secondValve means whenever the pressure within said buoy exceeds the pressureof such medium by less than such last-mentioned predetermined value.

2. A distress signalling mechanism for submarines comprising acollapsible buoy adapted to be carried on a vessel in collapsedcondition, a reservoir containing a compressed gas, said reservoir beingcarried on said buoy, conduit means providing communication between saidreservoir and the interior of said buoy, valve means controlling flowthrough said conduit means and comprising an element having a surfacesubject to the pressure currently existing in the interior of said buoyand having a larger opposing surface subject to the current pressure ofthe circumambient medium, said element being movable, under the jointeffect of a pressure within the buoy exceeding the pressure of suchmedium by less than a predetermined value, to open said valve means topermit ow through said conduit, and movable to close said valve meanswhenever the pressure within said buoy exceeds the pressure of saidmedium by more than such predetermined value, and a second valve meanscontrolling communication between the interior of said buoy and thecircumambient medium, comprising an element having a surface subject tothe pressure currently existing in the interior of said buoy and anopposing surface subject to the current pressure of such circumambientmedium, and movable, under the joint effect of a pressure Within thebuoy exceeding the pressure of such medium by more than a predeterminedvalue higher than said first-mentioned predetermined value, to open saidsecond valve means, but movable to close said second valve meansWhenever the pressure within said buoy exceeds the pressure of suchmedium by less than such lastmentioned predetermined value.

3. A distress signalling mechanism for submarines comprising acollapsible buoy adapted to be carried on a Vessel in collapsedcondition, a reservoir containing a compressed gas, conduit meansproviding communication between said reservoir and the interior of saidbuoy, valve means controlling ow through said conduit means andcomprising an element having a surface subject to the pressure currentlyexisting in the interior of said buoy and having a larger opposingsurface subject to the current pressure of the circumambient medium,said elementl being movable, under the joint eiect of a pressure Withinthe buoy exceeding the pressure of such medium by less than apredetermined value, to open said valve means to permit flow throughsaid conduit, and movable to close said valve means Whenever thepressure Within said buoy exceeds the pressure of said medium by morethan such predetermined value, and a second valve means controllingcommunication between the interior of said buoy and the circumambientmedium, and comprising an element having a surface subject to thepressure currently existing in the interior of said buoy and an opposingsurface subject to the current pressure of such circumambient medium,means biasing said second valve means toward closed position, and saidelement being movable, under the joint effect of a pressure within thebuoy exceeding the pressure of said medium by more than a predeterminedvalue, to open said second valve means, but movable to close said secondvalve means whenever the pressure within said buoy exceeds the pressureof such medium by less than such last-mentioned predetermined value.

CARROLL D. PLEAK.

